ACVR2B

A gene on chromosome 3p22 that encodes activin receptor type IIB, a receptor that forms a complex with other type-I and two type-II transmembrane serine/threonine kinase receptors for activin, a dimeric growth and differentiating factor belonging to the TGF-beta superfamily of structurally related signalling proteins. Type-I receptors are essential for signalling; type-II receptors are required for binding ligands and expression of type-I receptors. After activin binding, type-I receptors phosphorylate cytoplasmic SMAD transcription factors, which then translocate to the nucleus and interact directly with DNA or in complex with other transcription factors, playing roles in cell differentiation, growth arrest and apoptosis.